Printing plate



1,486,324 W. S. EATON PRINTING PLATE FiledDec. l3 1921 \mmmm Patented Mar. ll, i924.

hdddfi a VJILLIAM S. EATON, OF SAG HARBOR, NEW YORK.

PRINTING PLATE.

Application filed December 13, 1921.

T 0 all whom it may concern:

Be it known that I, WILLIAM S. EATON, a citizen of the United States, residing at Sag Harbor, in the county of Suffolk and State of New York, have invented certain new and useful Improvements in Printing Plates, of which the following is a specification, reference being had therein to the accompanying drawings, which form a part thereof.

My invention relates to printing plates, and more particularly to intaglio or under surface printing plates used in embossing printing presses.

It is the general practice in the production of plates for high grade embossed commercial or social printing, to reproduce the design upon the plate by means of an etching or like machine, the metal being removed by a deep out in an acid etching process, or in someinstances by means of a routing tool carried by an engraving machine. At the present time the acid etching process is used extensively, particularly as it permits the use of the same type of engraving machine for all kinds of work, and produces sharper and more regular lines in the plate.

Plates of the character to which my invention relates are ordinarily used for short runs upon a press, and must be of a standard height to secure a proper makeready in the press. Such plates, upon completion of a run of the press, are stored by the engraver, in anticipation of necessity for future use.

In embossing work, the intaglio lines are out in blocks of steel approximating one-half of an inch in thickness and varying in surface area according to the character of the design. In copper plate work, thin metal plates are used, so that in adapting a machine for different classes of work, it has heretofore been necessary to readjust the machine to accommodate the work point to plates of different thicknesses.

l/Vith the above conditions in mind, I have devised a printing plate which will have all the strength and rigidity of a thick metal block as ordinarily used in die work for embossed imprints, but which are so constructed as to permit the removal of a thin face plate from a thick base, thus not only facilitating the production of the face plate in the engraving or etching machine, and the handling thereof during the etching process,

Serial No. 522,018.

but permitting the convenient handling and storage of these plates while not in use. The invention contemplates the utilization of the base in the embossing press with different face plates, provision being made whereby face plates of different lengths may be accurately positioned with relation to the base, so as to secure accuracy of the position of the impression upon the printed sheet.

The invention consists primarily in a printing plate embodying therein a thick metal base, a relatively thin metal face plate bearing an undersurface design thereon, means carried by said base and adapted to engage the edges of said face plate including therein a movable member, means whereby said member is adapted to have pivotal movement upon one edge of said base, and means whereby said movable member may be oscillated to permit it to be engaged with, or disengaged from the edge of the face plate to permit the mounting of a plate upon, or the removal of the plate from the base; and in such other novel features of construction and combination of parts as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawings,

Fig. 1 is an isometric view of a printing plate embodying my invention;

Fig. 2 is a section on the line 2-2 of Fig. 1; and

Fig. 3 is an isometric view of the face plate removed from the base.

Like letters refer to like parts throughout the several views.

In the embodiment of my invention shown in the drawings, (4 indicates a rigid metallic base of a thickness of approximately oneeighth of an inch less than that of the ordinary standard die blocks used in embossing presses. Extending longitudinally along one edge of said base is an overhung beveled rim Z), the undercut portion of which is presented toward the top of the plate.

Carried by the opposite edge of said base and extending parallel with the rim 6 is a clamp bar 0 having a projecting fulcrum edge 0 adapted to engage the side face of the base (4 adjacent the bottom thereof, and a bevelled gripping edge 0 overhanging the top face of the base a. The height of the rim 7) and of the clamp bar 0 is slightly lower than the thickness of the customary die blocks, so that all portions of the base at including the clamp bar 0 will be below the printing plane and the operative plane of the inking rollers and wiping strip of an embossing press.

The clamp bar -0 is adjustably mounted in relation to the base a by means of a plurality of screws d co-operating with screwthreaded openings in the adjacent side wall of the base a.

In combination with said base a, 1 provide a face plate 6 which is substantially one-eighth of an inch in thickness, having theopposite longitudinal edges thereof bevelled or chamfered so as to pass under and be engaged by the overhung rim Z) and the gripping edge 0 of the clamp bar 0.

In this manner the plate 6 may be removed from, or mounted upon, the base a at will, so as to facilitate its mounting upon an etching or engraving machine, to form a design thereon by the removal of resist from the surface of the plate by the work point of the machine, and the subsequent etching operation; or the cutting of a design thereon by means of an ordinary routing tool.

This removability of the face plate 6 also permits the storage of said face plates in compact form as practiced with ordinary engraved copper plates.

The removability of the face plate a permits the base a to be used with different face plates, and since the length of different plates may vary to accommodate different designs, I provide the base a with graduations on the top surface thereof, indicated at f, so as to facilitate accuracy in the positioning of the face plate upon the base to secure the desired position of the design upon said plate with relation to the position in which it is to appear upon the printed sheet.

The construction of the clamp 0 with its fulcrum edge 0', by reason of the slight clearance afforded between the opening in said bar and the screws cl, will permit a very slight rocking movement of said plate about the fulcrum edge 0 when tightening the screws 0? for the purpose of securing the face plate 6 in position thereon. By reason of the bevelled overhang of the rim Z) and the gripping edge c of the bar 0, the tightening of the screws (Z will develop a wedging action of said rim and said gripping edge upon the face plate so as to not only firmly engage it between the rim and said edge, but to also force it firmly against the top of the base a throughout the entire length of the plate, the slight rocking action of the bar 0 about the fulcrum edge 0 supplementing this wedging action by a slight downward thrust.

When the screws d have been properly tightened, the base a and the plate 6 will rasasea form a printing block having substantially the same degree of rigidity as a solid metal block, the face plate being held firmly against displacement through the rubbing action of the inking rollers and the wiping strip thereover.

The co-operating bevelled undercut of the rim 6 and the gripping edge 0 and bevelled edges of the plate 6 will force said plate firmly upon the top of the base a so as to avoid any possibility of the great pressure to which plates used in embossing presses are subjected, causing displacement or deformation of the face, which will remain perfectly fiat upon the base a under all conditions of use.

It is apparent that the top of the base a must be a true plane, and that the plate 6 must be perfectly flat so as to fit snugly thereupon.

It is not my intention to limit the invention to the precise details of construction shown in the accompanying drawings, it being apparent that such may be varied without departing from the spirit and scope of the invention.

Having described the invention, what I claim as new'and desire to have protected by Letters Patent, is 1- l. A printing plate embodying therein a thick metal base, a relatively thin metal face plate bearing an undersurface design there on, means carried by said base and adapted to engage the edges of said face plate including therein a movable member, means whereby said member is adapted to have pivotal movement upon one edge of said base, and means whereby said movable member may be oscillated to permit it to be engaged with, or disengaged from the edge of the face plate to permit the mounting of a plate upon, or the removal of the plate from the base.

2. A printing plate embodying therein a thick metal base, a relatively thin metal face plate having its opposite longitudinal edges bevelled and bearing an undersurface design thereon, an undercut bevelled rim carried by and extending along one edge of said base, and adapted to engage one bevelled edge of said face plate, a movable clamp bar having a bevelled gripping edge carried by the edge of said base opposite said rim and adapted to engage the other bevelled edge of said face plate, and means whereby it is adapted to have pivotal movement upon one edge of said base, and means whereby said clamp bar may be forced toward, or permitted to have movement away from, said face plate to firmly secure it upon said base, or permit its removal therefrom.

3. A printing'plate embodying therein a thick metal base, a relatively thin metal face plate having its opposite longitudinal edges bevelled and bearing an undersurface design thereon, an undercut bevelled rim carried by and extending along one edge of said base, and adapted to engage one bevelled edge of said face plate, a movable clamp bar having a bevelled gripping edge carried by the edge of said base opposite said rim and adapted to engage the other bevelled edge of said face plate, and a fulcrum edge adapted to engage the side of said base adjacent the bottom thereof, and means operative between said gripping edge and said fulcrum edge whereby said clamp bar may be forced toward, or permitted to have movement away from, said face plate to firmly secure it upon said base, or permit its removal therefrom.

l. A printing plate embodying therein a thick metal base, a relatively thin metal face plate having its opposite longitudinal edges bevelled and bearing an undersurface design thereon, an undercut bevelled rim carried by and extending along one edge of said base, and adapted to engage one bevelled edge of said face plate, a movable clamp bar having a bevelled gripping edge carried by the edge of said base opposite said rim and adapted to engage the other bevelled edge of said face plate, and a fulcrum edge adapted to engage the side of said base adjacent the bottom thereof, and means operative between said gripping edge and said fulcrum edge whereby said clamp bar may be forced toward, or permitted to have movement away from, said face plate to firmly secure it upon said base, or permit its removal therefrom, said base having on the top surface thereof, graduation markings whereby a face plate may be accurately positioned with relation to its base.

In witness whereof I have hereunto affixed my signature, in the presence of two subscribing witnesses, this 8th day of December, 1921.

WILLIAM S. EATON. lVitnesses:

RosALYN O. HALLORAN, MARY HELLEMANN. 

